Method for making rheostats

ABSTRACT

THE DISCLOSURE RELATES TO A METHOD FOR MAKING RHEOSTATS. A SUBSTRATE IS PREPARED FOR SUPPORTING A RESISTIVE PATTERN WITH A FIRST CONDUCTIVE MEMBER AT ONE END, THE SUBSTRATE INCLUDING A SECOND CONDUCTIVE MEMBER FORMING AN ELECTRICALLY COMMON CONNECTION. A CONDUCTIVE MEANS IS POSITIONED OVER THE SUBSTRATE, THE CONDUCTIVE MEANS INTEGRALLY SUPPORTING A WIPER ELEMENT AND A TERMINAL PAIR. THE WIPER ELEMENT IS ROTATABLY SECURED TO THE SUBSTRATE, SO THAT ONE END MAKES ADJUSTABLE   AND CONTIGUOUS CONTACT WITH THE RESISTIVE PATTERN, WHILE THE OTHER END IS ELECTRICALLY CONTINUOUS WITH THE ELECTRICALLY COMMON CONNECTION. THE TERMINAL PAIRS ARE THEN SECURED TO THE FIRST AND SECOND CONDUCTIVE MEMBERS, AND FINALLY THE TERMINAL PAIRS AND THE WIPER ELEMENT ARE SEVERED FROM THE CONDUCTIVE MEANS WHERE THEY ARE INTEGRALLY JOINED.

Feb. 9,1971 BURKE 3,561,113

METHOD FOR MAKING RHEOSTA'I'S Filed Jan. 30, 1969 F FIG.|

O F|G.2 ZG'A 32*" -4 CLARENCE A. BURKE L INVENTOR.

ATTORNEYS United States Patent US. Cl. 29-621 6 Claims ABSTRACT OF THEDISCLOSURE The disclosure relates to a method for making rheostats. Asubstrate is prepared for supporting a resistive pattern with a firstconductive member at one end, the substrate including a secondconductive member forming an electrically common connection. Aconductive means is positioned over the substrate, the conductive meansintegrally supporting a wiper element and a terminal pair. The wiperelement is rotatably secured to the substrate, so that one end makesadjustable and contiguous contact with the resistive pattern, while theother end is electrically continuous with the electrically commonconnection. The terminal pairs are then secured to the first and secondconductive members, and finally the terminal pairs and the wiper elementare severed from the conductive means where they are integrally joined.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates to a method for making rheostats. (2) Description of the priorart While present day demands in the art of manufacturing electricalcomponents are primarily addressed to miniaturization, nevertheless, theconsideration of reducing costs continues to play an important, and insome applications, the dominant role.

Various cost reducing techniques are of course known in the art ofelectrical component manufacture. As an example, US. Pat. 2,887,558 toTally discloses the use of a ladder stamping member, to facilitate themass production of resistors suitable for printed circuitryapplications.

SUMMARY OF THE INVENTION The present invention relates to a method forproducing rheostats. In a preferred embodiment of the invention asubstrate is prepared having a resistive pattern with a first conductivemember at one extremity, the substrate also supporting a secondconductive member. The substrata are then laid in tandem on an assemblyline. A conductive means is prepared having a configuration suitable forintegrally supporting terminal pairs and wiper elements; such conductivemeans are then positioned over the substrata, and each wiper elemen isrotatably secured to a respective substrate so that the wiper element isboth in adjustable contact with the resistive pattern, and iselectrically continuous with said second conductive member. Next, eachterminal pair is secured to the first and second conductive membersrespectively. Finally, the terminal pairs and the wiper elements aresevered where they are joined integrally with the conductive means toprovide a plurality of completed rheostats.

This invention has for its object providing a method for fabricatingrheostats which will produce a low cost rheostat by reason of thesimplicity of the method of manufacture.

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The invention is more particularly described and illustrated inconnection with the accompanying drawing which shows diagrammatically anembodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exploded view showing thecomponent parts of the final assembly for a rheostat produced inaccordance with the method of the instant invention; and

FIG. 2 is a top plan view showing the component parts in position priorto the final step in the method of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2the entire method is accomplished using three major components indicatedgenerally at: 10, 12 and 14.

The component 10, which is most clearly shown in FIG. 1, is firstprepared on a dielectric substrate 16, centrally apertured at 18, onwhich is arranged a resistive pattern 20, (which may be arcuate),secured in any convenient manner and terminating at one extremity in aconductive member 22; a second conductive member 24 is secured to thesubstrate 16, and has a configuration, which in this illustrativeembodiment, includes an aperture coincident with aperture 18 in thesubstrate.

The part 12 is prepared as a conductive means which may have anyconvenient configuration such as a ladder structure with rungs at 26,28. Integral with the conductive means are a terminal pair 30, 32, and awiper element 34; the Wiper element 34 includes a protuberance or dimple36 and an aperture 38.

The third major part of the assembly is the eyelet 40 for rotatablysecuring the wiper element 34, although it will be readily appreciatedthat any fastening means may be used.

In the method of the invention, the substrate 10 is first prepared, andthe substrata, (only one substrate is shown in FIG. 2), are thenarranged along an assembly line with each respective substrate intandem. Next, the conductive means 12 is prepared, and in the ladderconfiguration, here illustrated, it is positioned over the dielectricsubstrate 10, with each substrate 10 being located between successiverungs 26, 28 as shown in FIG. 2.

Next, the wiper element 34 is rotatably secured to the dielectricsubstrate 10. In this embodiment an eyelet 40 is then passed through theaperture 38 in the wiper element, and through the aperture 18 in thesubstrate 10, and by mechanical pressure it is movably secured to thesubstrate 10, with the protuberance or dimple 36 contiguous with theresistive pattern 20.

Next, the terminal pair 30, 32 are secured to conductive members 22 and24, respectively, in any convenient manner such as by soldering asindicated at 42, 44.

Finally, the wiper element 34 and the terminals 30 and 32 are separatedfrom the conductive structure 12, by shearing along the lines asindicated at 46, 48 and 50, respectively.

This entire operation can take place at an accelerated pace, so that therheostats can be produced in great numbers. The finished rheostat thenhas the general configuration shown in the exploded view in FIG. 1 withthe wiper element 34 being enabled to move along the arcuate resistivepattern 20, the protuberance or dimple 36 providing a means forarresting rotary displacement of the wiper element at the selected pointalong the resistive pattern 20.

The invention has been described in detail with particular references toa preferred embodiment thereof but 3 it will be understood thatvariations and modifications can be efi'ected within the spirit andscope of the invention.

I claim:

1. A method for making a rheostat having a pair of terminals, oneterminal being at one extremity of a resistive pattern, and a wiperelement having one end electrically common with the other one of saidterminal pair, the other end of said Wiper element making adjustablecontact with said resistive pattern, said method comprising the stepsof:

(a) preparing a substrate supporting said resistive pattern terminatingat one end in a first conductive member, with a second conductive memberon said substrate at said electrically common point;

(b) positioning conductive means over said substrate,

said conductive means having formed integral therewith said terminalpair and said wiper element;

() securing said wiper element to said substrate so that said wiperelement is both in adjustable contact with said resistive pattern and iselectrically continuous with said second conductive member;

(d) securing said terminal pair to said first and second conductivemembers respectively; and

(e) severing said terminal pair and said wiper element where they arejoined integrally with said conductive means.

2. A method for making rheostats, each rheostat comprising a pair ofterminals, one terminal being at one extremity of a resistive pattern,and a wiper element having one end electrically common with the otherone of said terminal pair, the other end of said wiper element makingadjustable contact with said resistive pattern, said method comprisingthe steps of:

(a) preparing substrata, each respective substrate supporting saidresistive pattern terminating at one end in a first conductive memberwith a second conductive member on said respective substrate at saidelectrically common point;

(b) arranging said substrata with each respective substrate in tandem;

(c) preparing conductive means having formed integral therewith terminalpairs and wiper elements;

((1) positioning said conductive means over said arranged substratarespectively;

(e) securing each respective wiper element to a respective substrate sothat each wiper element is both in adjustable contact with saidresistive pattern and is electrically continuous with said secondconductive member;

(if) securing said terminal pairs to said first and second 'conductivemembers respectively; and

(g) severing each of said terminal pairs and each of said wiper elementswhere they are respectively joined integrally with said conductivemeans.

3. A method for making a rheostat having a pair of terminals, oneterminal being at one extremity of an arcuate resistive pattern, and awiper element having one end electrically common with the other one ofsaid terminal pair, the other end of said wiper element making movingcontact with said arcuate resistive pattern, said method comprising thesteps of:

(a) preparing a substrate supporting said arcuate resistive pattern,said arcuate resistive pattern terminating at one end in a firstconductive member, with a second conductive member on said substrate atsaid electrically common point;

(b) positioning conductive means over said substrate,

said conductive means having formed integral therewith said terminalpair and said wiper element, said wiper element having a protuberancemeans at said other end adapted for said moving contact with saidarcuate resistive pattern;

(c) rotatably securing said wiper element at said one end so that saidwiper element is electrically connected with said second conductivemember, and said protuberance means is contiguous with and movable alongsaid arcuate resistive pattern;

(d) securing said terminal pair to said first and second conductivemembers respectively; and

(e) severing said terminal pair and said wiper element where they arejoined integrally with said conductive means.

4. A method for making rheostats, each rheostat comprising a pair ofterminals, one terminal being at one extremity of an arcuate resistivepattern, and a wiper element having one end electrically common with theother one of said terminal pair, the other end of said wiper elementmaking moving contact with said arcuate resistive pattern, said methodcomprising the steps of:

(a) preparing substrata, each respective substrate supporting saidarcuate resistive pattern, said arcuate resistive pattern terminating atone end in a first conductive member, with a second conductive member onsaid respective substrate at said electrically common point;

(b) arranging said substrata with each respective substrate in tandem;

(c) preparing conductive means having formed integral therewith terminalpairs and wiper elements each wiper element respectively having aprotuberance means at said other end for making moving contact with saidarcuate resistive pattern;

(d) positioning said conductive means over said arranged substratarespectively;

(e) rotatably securing respectively each wiper element at said one endso that respective wiper element is electrically connected with saidsecond conductive member, and said protuberance means is contiguous withand movable along said arcuate resistive pattern;

(f) securing said terminal pairs to said first and second conductivemembers respectively; and

(g) severing each of said terminal pairs and each of said wiper elementsrespectively where they are joined integrally with said conductivemeans.

5. A method for making a rheostat having a pair of terminals, oneterminal being at one extremity of an arcuate resistive pattern, and awiper element having one end electrically common with the other one ofsaid terminal pair, the other end of said wiper element making movingcontact with said arcuate resistive pattern to vary the ohmic magnitudepresented across said terminal pair, said method comprising the stepsof:

(a) preparing a dielectric substrate supporting said arcuate resistivepattern, said arcuate resistive pattern terminating at one end in afirst conductive member, with a second conductive member at saidelectrically common point, and having a configuration including a firstaperture concentric with a second aperture in said dielectric substrateand with said arcuate resistive pattern;

(b) positioning conductive means over said dielectric substrate, saidconductive means having formed integral therewith said terminal pair andsaid wiper element, said wiper element having a third apertureconcentric with said first and second apertures, and including aprotuberance means adapted for contact with said arcuate resistivepattern;

(c) rotatably securing said wiper element through said first, second andthird apertures so that said wiper element is electrically connectedwith said second conductive portion, and said protuberance means iscontiguous with said arcuate resistive pattern;

(d) securing said terminal pair to said first and second conductivemembers respectively; and

(e) severing said terminal pair and said wiper element where they arejoined integrally with said conductive means.

6. A method for making rheostats each rheostat comprising having a pairof terminals, one terminal being at one extremity of an arcuateresistive pattern, and a wiper element having one end in electricallycommon union with the other one of said terminal pair, the other end ofsaid wiper element making adjustable contact with said arcuate resistivepattern to vary the ohmic magnitude presented across said terminal pair,said method comprising the steps of:

(a) preparing dielectric substrata, each respective substrate supportingsaid arcuate resistive pattern, said arcuate resistive patternterminating at one end in a first conductive member, With a secondconductive member at said electrically common union, and having aconfiguration including a first aperture concentric with a secondaperture in said respective dielectric substrate and with said arcuateresistive pattern;

(b) arranging said substrata with each respective dielectric substratein tandem;

(c) preparing conductive means having formed integral therewith terminalpairs and Wiper elements, each of said wiper elements having a thirdaperture concentric with said first and second apertures, and includinga protuberance means adapted for contact with said arcuate resistivepattern;

(d) positioning said conductive means over said arranged substrata;

(e) rotatably securing respectively each wiper element to saidrespective dielectric substrate through said first, second and thirdapertures, so that each re- References Cited UNITED STATES PATENTS1,691,251 11/1928 Rathbone 29-621X 2,173,186 9/1939 Swartz et al 2961OX2,269,136 1/ 1942 Tellkamp 29621X 2,606,985 8/1952 De Bell 29621X2,756,307 7/ 1956 Schwartz 29620 3,095,636 7/1963 Ruckelshans 29-6103,200,010 8/ 1965 Place, Sr. 29-620X 3,464,104 9/ 1969 Towner et a1.29-589X 3,497,947 3/ 1970 Ardezzone 29589X JOHN F. CAMPBELL, PrimaryExaminer R. I. SHORE, Assistant Examiner US. Cl. X.R.

